Homeostatis/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby. A boy, Tim, and a robot, Moby, are sitting on a couch in front of two large glass doors. Hard rain can be heard coming down and can be seen through the doors. Tim begins reading from a typed letter he holds in his hand. Text reads: Dear Tim and Moby, What is homeostasis? From Oded. TIM: That's a great question, Oded. We all know that the conditions in the outside world change all the time. The rain coming down the glass doors behind Tim and Moby stops. TIM: Huh. But things are different inside your body. The conditions in there don't really change at all. In most circumstances, our body temperature stays within a relatively narrow range. The video show Tim with a thermometer in his mouth. TIM: That's because humans are warm-blooded animals, just like cats and dogs and camels. The video shows Tim sitting on the couch with a cat on his lap and a dog beside him. A camel walks into the screen. The camel snorts and brown goo lands on Tim's cheek. TIM: Eww! Cold-blooded animals like lizards and fish depend on their environment to regulate their body temperature. The screen is divided into two equal sections. in the left section, an image shows a lizard. In the right section, an image shows a school of fish. TIM: Anyway, the temperature and the chemical balance inside your body have to stay the same for you to function. The video shows Tim talking and the outline in the shape of a woman is shown behind him. Within the outline is a green glow that fades to black and white. TIM: To maintain this "sameness," which is called homeostasis, your body regulates itself in a bunch of ways. Thermoregulation is the way your body keep its temperature steady at around 37 degrees Celsius, or 98.6 degrees Fahrenheit, no matter how hot or cold it is outside. Here's how it works. The hypothalamus is a part of your brain that acts as a sort of a thermostat. The video shows an image of a human brain. A small, cone-shaped section located near the bottom and towards the center of the brain is blinking yellow. TIM: When your body temperature starts to rise and fall, a special team of nerves and hormones called a feedback system sends a warning to the hypothalamus. The video shows an image of a group of figures with two dots and a line near the top representing two eyes and a mouth. The figures look like carrots. Some have domed-like heads while the others have spikey heads. MOBY: Beep! TIM: Moby made this... this thing to show how feedback works. The video shows an image of Moby standing next to the tank. A horizontal dotted line divides the tank into two equal section. The tank is filled up to the dotted line with water. On the outside of the tank, there is a light attached to its upper section and a light attached to its lower section. Moby is holding a garden hose with the end placed inside the tank. The video shows an image of Moby turning on the water to the spigot where the hose is attached at the other end. Water begins running out of the hose into the tank. Running water is heard. TIM:When the water level gets to high, he opens the valve at the bottom to let some out. As the water level increases, a beep is heard and the light in the upper portion of the tank flashes red. TIM: If there's too little water, he adds more, to keep the water at just the right level. As the water decreases, a beep is heard and the light in the lower portion of the tank flashes red. The video shows an image of Moby reaching off screen to turn the knob that controls the spigot. Squeaking is heard. the tank begins to fill with water again. TIM: The feedback systems in your body behave in "much the same way." Most feedback is negative, meaning that the change is bad new and needs to be countered. It thermoregulation, it's negative feedback that tells the hypothalamus when you're overheated and you need to sweat. The video shows a image of a girl sweating on a hot, sunny day. TIM: Or that you're really cold, and you may need to shiver in order to generate heat. The video shows an image of a girl shivering on a cold, snowy day. TIM: Feedback can be positive, too, meaning that the change in your body is a good thing, and should even be increased for a while. When a pregnant woman goes into labor, it's positive feedback controlling the contractions that push the baby out. The video shows an image of a woman lying in a hospital bed straining while a man next to the bed holds her hand. TIM: Another part of the hypothalamus's job is to make you run a fever when you're sick. At those times, the thermostat resets itself to a higher temperature to give your body more heat energy to fight infection. The video shows and image of Tim lying in bed with a thermometer in his mouth. TIM: But homeostasis isn't just about regulating body temperature. For example, your excretory organs get rid of chemical waste that's poisonous to your body. The video shows an image of Moby sitting on a toilet. TIM: A part of you brain called the respriatory center make sure that you have the right oxygen and carbon dioxide mix in your blood at all times. The video shows an animation of doughnut shaped figures representing red blood cells moving from left to right along the screen while holding a green oblong shape. The figures moving across the bottom of the screen are moving from right to left across the screen while holding a blue oblong shape. TIM: And your immune system defends you from invading viruses, bacteria, and allergens that don't belong in your body. The video shows an image of a group of evil-looking figures with many sharp points and jagged teeth. The video shows an animation of the green figures exploding into a starburst one by one. The video shows Tim and Moby sitting on the couch. TIM: Homeostasis ensure that the environment inside your body remains stable no matter how crazy the outside world gets. MOBY: Beep? TIM: No, I'm not going to feel your forehead. MOBY: Beep? TIM: Because you don't have a fever. MOBY: Beep? TIM: Well, you're not warm-blooded. You don't have blood. Aw, you forget to turn that water thing off! The video shows the room fulling with water. TIM: You just exist to get me in trouble, don't you?Category:BrainPOP Transcripts